Crepe fabric and method of making same



Patented July 7, 1942 CREPE FABRIC AND METHOD OF MAKING SAME Nathaniel Crowell Shan bec. Canada,

e, .Drummondville, Queassignor to Celanese Corporation of America, a corporation of Delaware l lo Drawing. Application April 22, 1939,

Serial No. 269,415

3 Claims. (Cl. 8114.5)

This invention relates to the manufacture of crepe'fabric containing organic derivatives of cellulose and to the production therefrom of fabrics exhibiting crepe effects,

Anobject-of this invention is the economic and expeditious productionof crepe fabrics comprising yams or threads containing organic derivatives of cellulose.

A further object of this invention is the production of crepe effects upon fabrics containing organic derivative yarns or threads which shrink and buckle when containing crepe yarns of lower degree of twist, or in shorter periods of time, or at lower temperatures when treated in a creping bath.

Other objects of this invention will appear from the following detailed description and the appended claims.

It has' been previously found that if yarns of cellulose acetate or other organic derivative of cellulose have a high twist imparted thereto in the presence of hot aqueous media, such as steam or hot water, they produce crepe effects in fabrics containing them when given treatment in hot scouring baths.

I have found that if fabrics containing fila- As stated above, the crepe promoting agent I that is incorporated with or applied to the fabric in accordance with this invention comprises a substance that has delayed solubility in water,

by which is meant a substance of colloidal nature which is not-freely soluble in water, but which when treated with water, especially'at the temperature of the creping bath absorbs water and swells. Examples of thecrepe promoting agents that may be employed in this invention are proteins, whether of animal or vegetable origin such as proteins obtained from soya beans, gelatin or modified gelatine, or other albumens such as egg albumen, casein, and sericin; proteins which have been treated with formaldehyde or other aldehydes; gums, such as gum tragacanth; starches;

methyl cellulose that swells in hot water, alkali ments, yarns or threads of organic derivative of cellulose which have been highly twisted in the aqueous creping or boil-off bath, whilethe fabric contains a crepe promoting agent, many advantageous results are obtained. Thus, fabric containing cellulose acetate yarn and treated in a boil-off bath while containing my crepe promoting agent produces at least as good crepe effects as fabrics containing cellulose acetate yarn that has not been treated with my, agent prior to the boil-off when (1) it contains cellulose acetate yarns of less twist, (2) fabric containing it is treated in a creping bath of lower temperatures,

organic derivative of cellulose may be employed in the manufacture of the new crepe threads, for

' presence of hot aqueous media, are treated in an example, filaments, yarns or threads containing cellulose esters such as cellulose acetate, cellulose butyrate and cellulose propionate, and cellulose ethers such as ethyl cellulose and benzyl cellulose. Theinvention, howeveiyis of especial value and will be described more particularly in connection with the production of crepe fabrics thread is drawn off over containing yarns orithreads of cellulose acetate. 55

ture of the bath the soluble cellulose ethers such as ethyl cellulose and hydroxy ethyl cellulose; etc.

In carrying out this invention any appropriate means may be employed for applying the crepe promoting agent to the fabric- Preferably the fabric is soaked in an aqueous bath containing the crepe promoting agent for a sufficiently long time thoroughly to impregnate the fabric. This is conveniently done by soaking the fabric while in skein form in an aqueous bath containing the crepe promoting agent for a period of /2 to 2 hours, while the bath is at an elevated temperature of to less time required.

. The fabric may be dried after impregnation with the aqueous bath of crepe promoting agent, prior to its treatment in the boihclfor creping bath. v V The bath employed in accordance with this invention contain such concentration of the crepe promoting agentas to impart thereto a consistency that is convenient, which concentration may be from to 10%. The amount of this emulsion to be applied to thefabric of cellulose acetate is such' that from to 10% of the crepe promoting agent, based on the weight of the fabric, is retained thereon, depending upon the nature of the agent employed.

As statedabove, the fabric treated by this invention contains filaments, yarns or threads which have been twisted in the presence of hot aqueous fluids such as steam or hot water; for instance as is described in U. .8. Patents Nos. 2,088,628 and 2,089,19l. This twisting may be effected on a deviceof the kind. in which the package through a guide fixed substantially in line with the axis of rotation of the package and C., the higher the tempera-- the head of,a rotating hot aqueous fluid during the actual application of twist. The twisting spindle, the guide fixed in line with the axis of the spindle and the device for applying the hot aqueous fluid to the filaments, yarns or threads should be so arranged that the twist resulting from the rotation of the package is at least partially inserted while the thread is in contact with the hot aqueous fluid.-

where, steam is employed as the hot aqueous fluid steaming may conveniently be eflected by allowing the thread to pass through a suitable chamber supplied with steam, preferably under such conditions that moisture is present. The

chamber is provided with small holes, top and bottom, to permit passage of the thread, and also with a steam inlet. If desired, a single steam chamber may be arranged to serve anumber of twisting devices, being provided with inlet and outlet holes for the thread of each twisting device. Such an apparatus may conveniently consist of a horizontal pipe mounted over a row of twisting devices and provided with,eyes of porcelain, stainless steel, or other suitable material at appropriate points on top and bottom for the entrance and exit of the threads. The diameter of the pipe should be such as to aflord the threads the requisite length of travel in the steam. Alternatively, a pipe having a smaller diameter and may be provided with means adapted to lead away and prevent from reaching the twisting spindle any liquid issuing from the hole. If desired, the hole may take the form of a short tube of fine bore, fixed in the receptacle, whereby the flow of liquid from the receptacle at the point of entrance of the thread may be reduced.

The duration of the treatment with hot water may be relatively short, such as may be secured when the thread is travelling at a speed of 2 to 10 meters per minute and is in contact with hot water for 1 to 3 inches of its travel. More prolonged treatments may. however, be employed.

Very good results may be obtained by usin hot water at temperatures of 85 to 100 C. Preferably the water should be as hot as possible and temperatures of, for instance, 95 to 100 C. are to I be recommended. If desired, the hot water may be employed under pressure, for example, 2 to 10 or 15 pounds or more per square inch. The use of pressure enables the water to be employed at higher temperatures than is possible under atmospheric pressure. By using pressure, therefore, the temperature of the water may be above may be'used, in which case the pipe may be provided with hollow nipples communicating therewith and through which the yarn passes, the nip ples being of sufllcient length to provide, together with the diameter of the pipe, the requisite length of travel in the steam.

The presence of the desired moisture may be assured by supplying wet steam to the steaming device and/or by arranging for the condensation of steam to supply the requisite amount of moisture. For instance, small traps for condensed water may be provided at suitable intervals in the steaming chamber and steam injected there- 100 C. and to the boiling point thereof at the pressure employed. Water may be employed un der pressure, however, when the temperature is below 100 C.

The crepe twisting may be applied in a single stage. If desired, however, the crepe twist may be applied in two or more stages, at least the final stage of twisting being effected while treating the thread with but aqueous fluid, as described in U. S. Patent No. 2,088,587. a

When the crepe twist is applied in two or more stages the advantages of the process may'be obtained when. not only the final stage of the crepetwisting but the earlier stage or stages of twisting are also effected while treating the thread with through by means of small pipes or orifices. An-

other method of insuring the presence of moisture is to wet the thread with water. For example, the bobbins of thread may be wetted before the twisting operation or, better, watermaybe applied to the by. means of a wick or other device after the thread leaves the spindle and prior to its entering the steaming device. 7

Steam at slightly above atmospheric-pressure, or at a pressure of 1 to 2 centimeters of water, is most conveniently employed. If desired, how-.

hot aqueous fluid. In fact, it is of great advantage to effect, while treating the thread with hot aqueous fluid, any application of twist beyond the 'point at which twisting would result in weakening of the thread if the said twisting were effected without the hot aqueous fluid treatment.

a The total twist applied in accordance with the process of the present inevntion may vary within wide limits, and the crepe figure in the fabric may be regulated according to requirements.

The total twist desirable in any particular case depends upon a. number of factors, including the precise efifects required, the number of filaments,

- and the denier of the thread.

ever, the steaming may be effected with steam at any desired super-atmospheric pressures, e. g.

steam at 10. to 25 lbs. per square inch.

A steaming treatment of relatively short duration, such as maybe secured by causing the yarn to pass through steam in a path of about 1 to 6 inches at a speed of from 2 to 10 meters per minute has been found to give satisfactory re-- suits; Longer treatments may, however, be employed. For example, the yarn may be passed at the said speeds through 6 'inches to 12 inches or. more of steam.

The treatment of the thread with hot water during twisting may be eifectedby drawing the thread off from a twisting spindle and passing it upwardly through a small hole in a suitable receptacle containing hot water, the thread then passing to a winding device. The hole may be,

for example, about a; of an inch in diameter An important advantage of my process is that good crepe effects may be obtained with fabrics containing cellulose acetate yarn of lower degree of twist than has been attainable heretofore. The number of turns to be employed may be from 55 to 90 turns per'inch', depending onthe eflects desired, the greater the number of turns, the less temperature and/or time of treatment being required in the creping bath.

While the process of this invention enables production of threads which yield satisfactory crepe eifects without a special treatment, other than the twisting andhot aqueous fluid treatment characteristic of the process, other treatments may, if

desired, be employed further to improve the properties of the crepe threads and/or fabrics producedtherefrom. Thus enhanced crepe effects may be obtained by treating the fabrics containing the crepe threads with aqueous solutions of saponifying agents such as the hydroxide or carbonates of sodium potassium or ammonium to superficially saponiiy the cellulose acetate yarns,

pad the fabric with an aqueous solution of an alkaline material, say a solution containing to 40 grams per liter of sodium hydroxide and then drying the fabrics on heated cans.

The highly twisted crepe threads may be incorporated in the fabrics in various ways, for example, the weft alone may be wholly or partially composed of such threads or the warp may also contain them. Valuable fabrics may be produced by employing warp threads of relatively low twist and in the weft both crepe threads having a left-hand twist and crepe threads having a right-hand twist, pairs of threads of left-hand twist alternating with pairs of threads of righthand twist.

If desired, the cellulose acetate crepe threads may be associated in the fabrics with highly twisted crepe threads of other materials, e. g. of

natural silk or regenerated cellulose, or with highly twisted threads produced by other processes. Where the fabrics contain threads of low twist'these may be wholly of cellulose acetate or wholly or in part of other materials, e. g., natural silk or regenerated cellulose. The cellulose acetate crepe threads may be doubled with ordinary cellulose acetate yarns or yarns of other materials prior to incorporation in the fabric.

Fabrics containing highly twisted crepe threads impregnated with the crepe promoting agent in accordance with the invention may be subjected to a hot aqueous treatment in the manner commonly adopted in connection with fabrics comprisinghighly twisted yarns of natural silk. By proper control of the temperature and strength of the crepingbath, delustering of the cellulose acetate may be avoided, the proper amount of creping being obtained by control of temperature.

The use of a separate creping bath is not always necessary, as the creping, in some instances,

cellulose acetate yarn of 100' denier having 3 to- 4 turns per inch, and a weft of 62 picks per inch of cellulose acetate yarn of 170 denier having 68 turns per inch, which twist has been inserted in the presence of steam, the weft comprising yarn of right-hand twist alternating with yarnof lefthand twist, is treated.

may be carried out by treatment for a suflicient period in the solution containing the creping agent, which solution is maintained at elevated temperatures, say 95-100 C.

The fabric may be treated in the bath containing the creping agent and in the creping bath while in the form of hanks or skeins, or in full width and in single layers.

In order to illustrate my invention, but not by way of limitation, the following example is given:

I Example A fabric having a warp of 96 ends per inch of The fabric while in hank or skein form is soaked for 1 hour in an aqueous bath of 98 C. containing 5%.of the isolated protein derived from soya bean. It is then heated in a hot scouring creping bath of 98 C. for 3 hours.

The fabric which had an original width of 44% inches shrinks to a width of 32 inches, which involves a considerably greater shrinkage than experienced by the same fabric when boiled off without treatment with the soya bean protein. Moreover, the fabric so produced has a better hand and a more even crepe and better pebble effect than does the crepe fabric produced without the use of the protein.

,It is to be understood that the foregoing detailed description is merely given by way of illusin a fabric containing organic derivative of cellulose yarn which has been crepe twisted while it is subjected to the action of a hot aqueous fluid,

and then treating the fabric with a creping bath.

2. Process for the production of crepe effects on fabrics comprising yarn of filaments of cellulose acetate, which comprises incorporating a protein derived from soya beans in a fabric containing cellulose acetate yarn which has been crepe twisted while it is subjected to the action of a hot aqueous fluid, and then treating the fabric with a creping bath.

3. Process for the production of crepe effects upon fabrics, comprising impregnating a fabric containing cellulose acetate yarn which has been crepe twisted while subjected to the action of a hot aqueous fluid with a crepe promoting agent comprising a protein derived from soya beans by soaking the fabric in an aqueous bath of elevated temperatures containing the protein and then treating the fabric with a creping bath.

NATHANIEL CROWELL SHANE. 

